The boss of London's biggest minicab firm could face prosecution for telling his drivers to use bus lanes illegally, it emerged today.

Chairman of Addison Lee, John Griffin, 69, last month told his drivers to deliberately break the law by driving in bus lanes, claiming that it was “discriminatory” to restrict bus lane use to black cabs and not private hire vehicles.

The High Court forced Addison Lee to withdraw the instruction to break the law.

But Labour MP for Dudley, Ian Austin, wrote to the Metropolitan Police to ask whether Mr Griffin’s original instruction broke the law.

Transport for London (TfL) also asked whether any criminal offence had been committed in issuing the instruction, according to the Metropolitan Police.

In a written response to Mr Austin seen by The Times, Met Commander Adrian Hanstock wrote: “TfL also asked the MPS to establish whether any offences are apparent arising from Mr Griffin’s directive.

“Mr Griffin’s letter has been passed to the Crown Prosecution Service for consideration and the MPS are awaiting the outcome of this legal advice.”

In April it emerged that Addison Lee lost a lucrative contract with the Government. Their cars will no longer be used by ministers and civil servants after chief procurement officer John Collington, the Government official in charge of all contracts, wrote in an email to a blogger: “We expect all private hire vehicles in London to adhere to the prohibition on using bus lanes.

“In regard to Addison Lee, the only existing Government contract with the company will expire at the end of this month and is not being renewed.”